bpo-40071: Fix potential crash in _functoolsmodule.c (GH-19273)
Changes on 7dd549eb0893 made _functools compatible with
PEP-489 and we could have multiple modules instances loaded.
But, right now there is no way to make `kwd_mark` global into
a per module instance variable. kwd_mark is used on lru_cache_new
which does not have a reference to a PyModule*, necessary to use
PyModule_GetState.
PEP-573 will solve this problem and will allow us to move the global
state to per-module data and properly clear the state when unloading
a module instance.
This change temporarily disable cleaning of kwd_mark to avoid NULL
pointer dereference if we clear kwd_mark and other module instances
still alive use it.
diff --git a/Modules/_functoolsmodule.c b/Modules/_functoolsmodule.c
index dbe022e..f3d8658 100644
--- a/Modules/_functoolsmodule.c
+++ b/Modules/_functoolsmodule.c
@@ -1413,7 +1413,10 @@
static void
_functools_free(void *m)
{
- Py_CLEAR(kwd_mark);
+ // FIXME: Do not clear kwd_mark to avoid NULL pointer dereferencing if we have
+ // other modules instances that could use it. Will fix when PEP-573 land
+ // and we could move kwd_mark to a per-module state.
+ // Py_CLEAR(kwd_mark);
}
static int